Infrared spectrum technique was applied to analyzing the changes of surface —OH structures and characteristic adsorption peaks of the goethite and δ-MnO2 which had adsorbed Cu2+ under different ionic strengths (c( NaNO3 ) =0.01-1.0 mol/L). The results show that the surface free —OH participated in the adsorption of Cu2+ on goethite and δ-MnO2, the hydrogen ions of Fe—O—(H) and Mn—O—(H) were replaced by copper ions, resulting in the formation of Fe—O—( Cu ) and Mn—O—(Cu). With the ionic strength increasing, —NO2 from NO-3 of NaNO3 can be attached to the surfaces of goethite and δ-MnO2. After the adsorption of Cu2 + , the infrared spectrum of δ-MnO2 was not changed significantly, but that of goethite was inverse.%应用红外光谱研究不同离子强度(c(NaNO3)=0.01～1.0 moL/L)条件下,针铁矿和δ-MnO2吸附cu2+前后表面羟基结构及其特征吸收峰的变化.结果表明:表面游离羟基参与了针铁矿和δ-MnO2对Cu2+的吸附,其Fe-O-(H)和Mn-O-(H)结构中的H+被Cu2+取代,转变为Fe-O-(Cu)和Mn-O-(Cu);随介质离子强度的增加,NaNO3的NO-3能以-NO2的形式参与吸附反应并缔结在两种氧化物表面;δ-MnO2吸附cu2+后特征吸收峰未发生明显变化,而针铁矿则相反.
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